private static async Task <Tuple <string, string, string> > TitlePartitionAsync(WikiSite site, IWikiFamily family, string rawTitle, int defaultNamespace)
{
// Tuple<interwiki, namespace, title>
Debug.Assert(site != null);
Debug.Assert(rawTitle != null);
var title = rawTitle;
if (title.Length == 0)
{
goto EMPTY_TITLE;
}
var state = 0;
/*
* state accepts
* 0 LeadingBlank
* 1 Namespace / Interwiki
* 2 Page title
*/
string interwiki = null, nsname = null, pagetitle = null;
while (title != null)
{
var parts = title.Split(new[] { ':' }, 2);
var part = parts[0].Trim(' ', '_');
switch (state)
{
case 0:
if (part.Length > 0)
{
goto case 1;
}
// Initial colon indicates main namespace rather than default.
nsname = "";
state = 1;
break;
case 1:
// Make sure there's a colon ahead; otherwise we just treat it as a normal title.
if (parts.Length == 1)
{
goto case 2;
}
NamespaceInfo ns;
if (site.Namespaces.TryGetValue(part, out ns))
{
// This is a namespace name.
nsname = ns.CustomName;
state = 2;
}
else
{
if (family != null)
{
var normalizedPart = family.TryNormalize(part);
if (normalizedPart != null)
{
var nextSite = await family.GetSiteAsync(part);
if (nextSite != null)
{
// We have bumped into another wiki, hooray!
interwiki = normalizedPart;
site = nextSite;
// state will still be 1, to parse namespace or other interwikis (rare)
}
}
}
else if (site.InterwikiMap.Contains(part))
{
// Otherwise, check whether this is an interwiki prefix.
interwiki = part.ToLowerInvariant();
// For interwiki, we do not parse namespace name.
// Instead, we treat it as a part of page title.
nsname = null;
state = 2;
}
else
{
// So this is only the beginning of a normal title.
goto case 2;
}
}
break;
case 2:
pagetitle = Utility.NormalizeTitlePart(title, site.SiteInfo.IsTitleCaseSensitive);
goto END_OF_PARSING;
}
title = parts[1];
}
END_OF_PARSING:
Debug.Assert(pagetitle != null, "pagetitle != null");
if (pagetitle.Length == 0)
{
goto EMPTY_TITLE;
}
// nsname == null means that the expression has interwiki prefix, while family == null
if (nsname == null && interwiki == null)
{
nsname = site.Namespaces[defaultNamespace].CustomName;
}
return(Tuple.Create(interwiki, nsname, pagetitle));
EMPTY_TITLE:
throw new ArgumentException($"The title \"{rawTitle}\" does not contain page title.");
}
private static async Task <Tuple <WikiSite, string, string, string> > TitlePartitionAsync(WikiSite site, IWikiFamily family, string rawTitle, int defaultNamespace)
{
// Tuple<interwiki, namespace, title, targetSite>
Debug.Assert(site != null || family != null);
Debug.Assert(rawTitle != null);
var title = rawTitle;
if (title.Length == 0)
{
return(null);
}
var state = 0;
/*
* state accepts
* 0 LeadingBlank
* 1 Namespace / Interwiki
* 2 Page title
*/
string interwiki = null, nsname = null, pagetitle = null;
while (title != null)
{
var parts = title.Split(new[] { ':' }, 2);
var part = parts[0].Trim(' ', '_');
switch (state)
{
case 0:
if (part.Length > 0)
{
goto case 1;
}
// Initial colon indicates main namespace rather than default.
nsname = "";
state = 1;
break;
case 1:
// Make sure there's a colon ahead; otherwise we just treat it as a normal title.
if (parts.Length == 1)
{
goto case 2;
}
string normalizedInterwikiPrefix;
if (site != null && site.Namespaces.TryGetValue(part, out var ns))
{
// This is a namespace name.
nsname = ns.CustomName;
state = 2;
}
else if (family != null && (normalizedInterwikiPrefix = family.TryNormalize(part)) != null)
{
// This is a known prefix in the specified WikiFamily.
var nextSite = await family.GetSiteAsync(part);
if (nextSite == null)
{
Debug.Assert(false, $"{family} returned null for prefix: {normalizedInterwikiPrefix}. " +
"IWikiFamily.TryNormalize should return null for in-existent interwiki prefixes.");
}
else
{
// We have bumped into another wiki, hooray!
interwiki = normalizedInterwikiPrefix;
site = nextSite;
// state will still be 1, to parse namespace or other interwikis (rare)
}
}
else if (site != null && site.InterwikiMap.Contains(part))
{
// Otherwise, check whether this is an interwiki prefix.
interwiki = part.ToLowerInvariant();
// For interwiki, we do not parse namespace name.
// Instead, we treat it as a part of page title.
nsname = null;
state = 2;
}
else
{
// So this is only the beginning of a normal title.
goto case 2;
}
break;
case 2:
pagetitle = Utility.NormalizeTitlePart(title, site?.SiteInfo.IsTitleCaseSensitive ?? true);
goto END_OF_PARSING;
}
title = parts[1];
}
END_OF_PARSING:
Debug.Assert(pagetitle != null, "pagetitle != null");
if (pagetitle.Length == 0)
{
return(null);
}
// nsname == null but interwiki != null means that the expression has interwiki prefix, while family == null
if (nsname == null && interwiki == null)
{
// If site is (still) null, we will have error reported in the caller.
nsname = site?.Namespaces[defaultNamespace].CustomName;
}
return(Tuple.Create(site, interwiki, nsname, pagetitle));
}